Treatment of thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP), characterized by thrombocytopenia and microangiopathic haemolytic anaemia, was almost universally fatal until the introduction of plasma exchange (PE) therapy in the 1970s. Based on clinical studies, daily PE has become the first-choice therapy since 1991. Recent findings may explain its effectiveness, which may include, in particular, the removal of anti-ADAMTS13 autoantibodies and unusually large von Willebrand factor multimers and/or supply of ADAMTS13 in acquired idiopathic or congenital TTP. Based on currently available data, the favoured PE regimen is daily PE [involving replacement of 1-1.5 times the patient's plasma volume with fresh-frozen plasma (FFP)] until remission. Adverse events of treatment are mainly related to central venous catheters. The potential reduction of plasma related side-effects, such as transfusion-related acute lung injury (TRALI) or febrile transfusion reactions by use of solvent-detergent treated (S/D) plasma instead of FFP is not established by controlled clinical studies. Uncontrolled clinical observations and the hypothesis of an autoimmune process in a significant part of the patients with acquired idiopathic TTP suggest a beneficial effect of adjunctive therapy with corticosteroids. Other immunosuppressive treatments are not tested in controlled trials and should be reserved for refractory or relapsing disease. There is no convincing evidence for the use of antiplatelet agents. Supportive treatment with transfusion of red blood cells or platelets has to be evaluated on a clinical basis, but the transfusion trigger for platelets should be very restrictive. Further controlled, prospective studies should consider the different pathophysiological features of thrombotic microangiopathies, address the prognostic significance of ADAMTS13 and explore alternative exchange fluids to FFP, the role of immunosuppressive therapies and of new plasma saving approaches as recombinant ADAMTS13 and protein A immunoadsorption.

Cardiogenic shock complicates successful treatment of refractory thrombotic thrombocytopenia purpura with rituximab

BACKGROUND

Treatment of thrombotic thrombo-cytopenia purpura (TTP) with daily therapeutic plasma exchange (TPE) may be accompanied by a variety of adjunctive interventions including most recently rituximab. Rituximab, a murine and human monoclonal antibody directed against CD20 antigen on B lymphocytes, is primarily used for treatment of non-Hodgkin's lymphomas. Because of severe and fatal infusion reactions including heart failure, rituximab carries a boxed warning.

CASE REPORT

A 20-year-old female presented with TTP. She underwent 17 daily (1 day skipped) TPE. Her platelet (PLT) count reached 150 x 10(9) per L and then gradually declined to 36 x 10(9) per L despite continuing TPE. Because of the refractory behavior of her disease, rituximab was administered. After the rituximab infusion, she developed a nonproductive cough which progressed to a productive cough, acute respiratory failure, chest pain, and hypotension and was moved to intensive care for management of biventricular cardiogenic shock (ejection fraction was 5%-10%). Once stable in the intensive care unit, TPE was resumed. Her PLT count reached 241 x 10(9) per L, and her lactate dehydrogenase decreased to normal after four TPEs. Her heart failure completely resolved and she was discharged. Rituximab was added to her medical record as a drug allergy.

CONCLUSION

Refractory TTP has been reported to respond favorably to rituximab when used as an adjunct. Interventions, however, can also carry significant risk as illustrated by the cardiogenic shock in our patient. Use of rituximab for refractory TTP should follow a careful assessment of benefits.

Splenectomy for the treatment of thrombotic thrombocytopenic purpura

Plasma exchange is the treatment of choice for patients with thrombotic thrombocytopenic purpura (TTP) and results in remission in >80% of the cases. Treatment of patients who are refractory to plasma therapy or have relapsing disease is difficult. Splenectomy has been a therapeutic option in these conditions but its value remains controversial. We report on a series of 33 patients with TTP who were splenectomised because they were plasma refractory (n = 9) or for relapsed disease (n = 24). Splenectomy generated prompt and unmaintained remissions in all except five patients, in whom remission was delayed (n = 4) or who died with progressive disease (n = 1). Four postoperative complications occurred: one pulmonary embolism and three surgical complications. Median follow-up after splenectomy was 109 months (range 28-230 months). The overall postsplenectomy relapse rate was 0.09 relapses/patient-year and the 10-year relapse-free survival (RFS) was 70% (95% CI 50-83%). In the patients with relapsing TTP, relapse rate fell from 0.74 relapses/patient-year before splenectomy to 0.10 after splenectomy (P < 0.00001). Two patients died from first postsplenectomy relapse. Although these results are based on retrospective data and that the relapse rate may spontaneously decrease with time, we conclude that splenectomy, when performed during stable disease, has an acceptable safety profile and should be considered in cases of plasma refractoriness or relapsing TTP to reach durable remissions and to reduce or prevent future relapses.

Methylene blue-photoinactivated plasma vs. fresh-frozen plasma as replacement fluid for plasma exchange in thrombotic thrombocytopenic purpura

BACKGROUND AND OBJECTIVES

Plasma exchange with fresh-frozen plasma (FFP) is the treatment of choice in thrombotic thrombocytopenic purpura (TTP). Methylene blue-photoinactivated plasma (MBPIP) has been proposed as a safer alternative to FFP, but its effectiveness in the treatment of TTP is not well established. The purpose of this study was to investigate whether MBPIP is as effective as FFP in the treatment of TTP by plasma exchange.

MATERIALS AND METHODS

A retrospective analysis was carried out of 56 TTP episodes, occurring between 1990 and 2003, which had been treated by plasma exchange. MBPIP was used for fluid replacement in 27 episodes and FFP in 29. The effect of plasma (MBPIP or FFP) on treatment outcomes was analysed by multivariate logistic regression.

RESULTS

Compared to patients treated with FFP, those receiving MBPIP had an increased risk of dying from progressive TTP [adjusted odds ratio (OR) = 31; 95% confidence interval (CI): 1.2 to > 100], a greater number of recurrences while on plasma exchange therapy (OR = 4.6; 95% CI: 1.2-17), and a lower probability of attaining a sustained remission within 9 days of starting plasma exchange (OR = 5.2; 95% CI: 1.3-20).

CONCLUSIONS

MBPIP seems to be less effective than FFP in the treatment of TTP. It is therefore prudent to avoid MBPIP until therapeutic equivalency to FFP has been established by randomized, controlled trials.

Laparoscopic splenectomy for chronic recurrent thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is a serious hematologic disorder with a high rate of morbidity and mortality when it fails to go into remission. The primary treatment is total plasma exchange. The addition of corticosteroids, chemotherapeutic agents, or antiplatelet agents is of unproven benefit, and splenectomy has been offered as salvage therapy in refractory cases. We performed laparoscopic splenectomy (LS) on two patients with chronic refractory TTP. The early and late postoperative courses, including hematologic data, are presented here. The mean duration of surgery was 113 minutes and the mean estimated blood loss was 35 mL. Mean hospital stay was 1.5 days. The early postoperative platelet count showed an immediate rise in both patients. After 19 months and 16 months of follow-up, respectively, both patients remain in remission without further episodes of TTP. Laparoscopic splenectomy is a safe and effective therapy for patients with chronic relapsing and refractory TTP. The inherent benefits of the minimally invasive approach, its low morbidity, short hospital stay, and faster recovery, are significant advantages for these patients.

Chronic relapsing thrombotic thrombocytopenic purpura in adult onset Still's disease

We report the first known case of chronic relapsing thrombotic thrombocytopenic purpura associated with adult-onset Still's disease. The patient presented with diffuse arthralgias, sore throat, and a maculopapular rash involving the trunk and extremities; she was hospitalized with fever and confusion. Thrombocytopenia, renal failure, and microangiopathic hemolytic anemia developed within several days. After a diagnosis of thrombotic thrombocytopenic purpura was made, she responded well to a series of plasma exchanges. Evaluation for infection, autoimmune disorders, and malignancy was negative. She was discharged to home in good condition, with normal renal function and normal platelet count. Two more episodes of TTP developed 7 and 9 months after the first hospitalization. The diagnosis of adult-onset Still's disease was then determined on the basis of clinical and laboratory criteria. She was successfully treated with plasma exchange, prednisone, and azathioprine. She later had splenectomy and has subsequently been without recurrence of thrombotic thrombocytopenic purpura for 2 years.

The management of idiopathic thrombotic microangiopathy. Changing trends

Thrombotic microangiopathy, including the two related syndromes thrombotic thrombocytopenic purpura and hemolytic-uremic syndrome, is a rare and severe multisystem disorder, due to widespread deposition of intravascular microthrombi consisting mainly of platelets, with subsequent consumption thrombocytopenia, microangiopathic hemolytic anemia, renal abnormalities, and neurologic disturbances. The epidemic, verotoxin-induced hemolytic-uremic syndrome, typically associated with prodromal diarrhea, mainly affects young children in small outbreaks. By contrast, idiopathic thrombotic microangiopathy generally affects adults in a sporadic form; it has a more devastating course and a less favourable outcome. Over 90% of the reported cases in the adult, when untreated, have progressed to death within three months of diagnosis. Since the introduction of plasma exchange, a dramatic change in the prognosis of the disease has taken place, although the mortality rate still remains considerable. Indeed, improved survival is the most striking feature of adult thrombotic microangiopathy compared to some decades ago. In the present article we will focus on the evolving concepts able to exert a considerable impact in the management of the adult idiopathic form of thrombotic microangiopathy.

Response to plasma exchange and steroids as combined therapy for patients with thrombotic thrombocytopenic purpura

We describe our experience in the management of 11 consecutive patients with thrombotic thrombocytopenic purpura (TTP) treated with a combined therapy of plasma exchange (PE) and steroids. Nine patients (82%) achieved complete remission (CR) after a median of 6 rounds of PE (range 2-22). There were 3 early relapses managed in the same way as the initial episode. One patient relapsed 23 months after diagnosis achieving CR with standard therapy; another patient suffered several relapses, and splenectomy was performed after the last one. Three patients died, 2 of them with resistant disease 9 and 38 days after diagnosis, and the remaining one died due to AIDS-related complications while he was in CR. Eight patients are alive in CR with a median follow-up of 38 months (range 8-74). The combination of PE and steroids is a well-tolerated and effective treatment of TTP, but improvements in therapy are needed to manage refractory patients.

The changing course of thrombotic thrombocytopenic purpura and modern therapy

Thrombotic thrombocytopenic purpura (TTP) is a multisystem disorder of unknown etiology. Pathologically, there appears to be an abnormal interaction between the vascular endothelium and platelets, but the primary event remains uncertain. While historically, TTP was a fatal disease, dramatic improvement in its outcome has occurred over the past two decades with the development of effective therapy. Plasma infusion or exchange remains the cornerstone of the treatment of TTP, along with corticosteroids, platelet inhibitor drugs, vincristine and splenectomy. This review summarizes the clinical findings, what is known of the pathogenesis and the available therapeutic modalities for TTP. In most cases, remissions can be attained and cures are now common. However, approximately half the patients will relapse. The clinical course at relapse is usually milder than the disease at presentation and less aggressive therapy may be needed. However, relapsing TTP still carries a significant mortality and preventive therapies are not always effective. Further progress may have to await an understanding of the fundamental etiology of this disease.